Lifetime and erosion of silver-based wire electrodes in an ultracorona in air

Anode erosion rates and lifetime-limiting parameters for a range of different silver-based wire materials have been investigated in a positive corona in atmospheric pressure air. The electrode wear was determined by measuring electrical resistance and diameter of the corona wires. Among the test materials were AgMn and AgCu alloys and Ag-coated stainless steel. As a rule, the erosion rate of AgCu and AgMn alloy anode wires decreases with the logarithm of the total amount of the transferred charge. It is likely that the anode lifetime of AgCu alloys with the content of Ag below the eutectic point are limited by initiation of the streamer mode with extremely ozone production.

► The lifetime of AgCu and AgMn alloy anode wires was studied in an ultracorona.
► The most lifetime among AgCu corona wires show the alloy with about 50% silver.
► The drop in erosion rate of the corona wires with the logarithm of time is observed.
► The ultracorona lifetime may be limited by streamers in the case of AgCu anode wires.